Long-Term Evolution (LTE) Time Division Duplex (TDD) provides a more flexible deployment than LTE Frequency Division Duplex (FDD) since LTE TDD does not require paired spectrum resources. In the current LTE specification, LTE TDD allows asymmetric Uplink/Downlink (UL/DL) allocations using seven semi-statically configured UL/DL configurations. The rate of change among different TDD configurations is semi-static because the system information provides the updates. Thus, a change in the TDD configuration is limited to a time scale of minimum of 640 milliseconds (ms). While the allocations can provide between 40% to 90% DL subframes, the semi-static UL/DL allocation may not match the instantaneous traffic situation. This mismatch is exacerbated in small cells deployment (e.g., malls, stadiums). For example, the number of UEs in small cells are typically small (e.g., less than 10 UEs), but, even though the traffic behavior of each UE tends to be similar, the traffic behavior may vary quickly over time. In these instances, this variance may lead to the overall traffic ratio of UL to DL changing rapidly. For example, different cells may behave differently at different periods or mass-calling events, or where the number of user equipment (UEs) in the cell is small. Though, neighboring cells may use different UL/DL configurations, which give rise to interference among eNodeBs (eNBs) and interference among UEs. A cell clustering interference mitigation (CCIM) scheme can provide an effective way to deal with these types of interference.
In general, a cell cluster can comprise one or more cells. The UL/DL TDD configuration for all cells within each cell cluster are identical, so that eNB-to-eNB interference and UE-to-UE interference can be mitigated within the cell cluster. Transmission directions in cells belonging to different cell clusters can be different in a subframe by selecting different UL/DL TDD configurations independently. In this way, the benefits of dynamic TDD UL/DL reconfiguration can be achieved. At the same time, by forming the cell clusters, eNB-to-eNB and UE-to-UE interference between cells in different cell clusters can be reduced.